Automatic production system and production process of a conductive backsheet with integrated encapsulating and dielectric layer for photovoltaic panels

Abstract

Automatic production system and production process for the automatic manufacturing of conductive backsheets with an integrated encapsulating and dielectric layer, for photovoltaic panels of the back-contact type. The system includes operating stations in sequence and is made up of at least one main line combined with a secondary line having a flow converging to a station of calibrated superimposition with fixing. The main line, on trays on a continuous conveying system, arranges and prepares the back supporting and conductive layer, whereas the secondary line forms the encapsulating and dielectric multi-layer element holed in correspondence of the electrical contacts comprising an automatic picking device which takes, roto-translates and holds said multi-layer element during processing and releases it only after the calibrated superimposition with fixing. The system is combined with a control system made up of at least four devices integrated with one another to enable calibration and check the automated processes.

The invention claimed is: 
     
       1. An automatic production system for assembly and control of a conductive backsheet for a photovoltaic panel with a back-contact architecture, the backsheet having an integrated encapsulating and dielectric layer, the system comprising:
 at least one processing main line; 
 at least one processing secondary line; 
 wherein the main line is combined with the secondary line, each of the main line and the secondary line having operating stations which are configured in sequence with a flow converging to a common station for calibrated superimposition and fixing to form the conductive backsheet with the integrated encapsulating and dielectric layer, the conductive backsheet being formed on a lower part of the main line, the conductive backsheet being carried on trays on a continuous conveying system, the encapsulating and dielectric multi-layer element being formed on an upper part of the secondary line so as to act as an insulating mask once superimposed and fixed on the conductive backsheet in the station; 
 an integrated control system for controlling positions and processes by comparison of an actual status with a predefined status, said integrated control system being made up of at least four control devices which are individually placed in correspondence to the station to be controlled and automatically integrated with one another so as to enable a processing or a passage of a product being processed to a following station, said secondary line comprising an automatic picking device which is continuous and permanent along the stations so as to take, move and hold individually the encapsulating and dielectric multi-layer element during processing and to release the encapsulated and dielectric multi-layer element only after fixing on the conductive backsheet at the station so as to combine and synchronize the main and secondary lines according to detections by said integrated control system and compensating for alignment and relative positioning of the encapsulating and dielectric multi-layer element with respect to the conductive backsheet; and 
 an unloading station for unloading the conductive backsheet from the tray, said unloading station having at least three branches of which one branch is for a continuous conveying of the tray and two branches are for a finished product. 
 
     
     
       2. The system of  claim 1 , wherein said automatic picking device has a mobile plate with a picking surface corresponding to the encapsulating and dielectric multi-layer element cut in a sheet, said mobile plate having openings with a pneumatic vacuum distributed uniformly, wherein some of the openings hold the sheet and other openings are for suctioning and conveying fumes and drilling residues so as to perform at least the following functions without interrupting the holding of the encapsulating and dielectric multi-layer element, the functions being taking individually the encapsulating and dielectric multi-layer element, translating the encapsulating and dielectric multi-layer element along said secondary line adherent and planar during processing, expelling the drilling residues, orientating encapsulating and dielectric multi-layer element horizontally, superimposing the encapsulating and dielectric multi-layer element onto the conductive backsheet in the station, exerting pressure and heating for fixing. 
     
     
       3. The system of  claim 1 , wherein said main line comprises:
 a first station for loading a single conductive backsheet into the tray for continuously conveying the conductive backsheet with the conductive layer facing upwardly; 
 a first control device which detects an exact position of the conductive backsheet with respect to the tray; 
 a second station with an arrangement of contacts which drills so as to form recessed seats and to insert contacting conductive elements for the back junction box; 
 a second control device that checks the working processes of said second station; 
 a third station of calibrated superimposition and fixing of the encapsulating and dielectric multi-layer element on the conductive backsheet, said third station synchronizing loading from the secondary line by the automatic picking device; 
 a third control device that checks working processes carried out at said third station; 
 a fourth station for unloading of the finished product from the tray, said fourth station having said at least three branches; 
 a fifth station for unloading of compliant products; and 
 a sixth station for unloading of non-compliant products. 
 
     
     
       4. The system of  claim 3 , wherein said second line comprises:
 a seventh station for preparation of the encapsulating and dielectric multi-layer element wherein a roller dispenser dispenses out the multi-layer sheet so as to enable a horizontal unwinding and cutting to size with a cutting tool; 
 an eighth station for drilling the encapsulating and dielectric multi-layer element from below; 
 a fourth control device for controlling the drilling by position detection; 
 a ninth station for synchronization wherein the detections by said integrated control system are combined such that said automatic picking device orientates and releases the encapsulating and dielectric multi-layer element in a correct position for fixing; and 
 an automatic picking device that exerts a pressure of up to 0.5 Kg/cm 2  on the surface of the encapsulating and dielectric multilayer element during calibrated coupling with the conductive backsheet, said automatic picking device being combined with said integrated control system and with said electronic controller so as to perform the movements with a maximum tolerances of +1-50 μm with respect to a center-of-gravity of the conductive backsheet. 
 
     
     
       5. The system of  claim 4 , wherein said automatic picking device comprises a direct heating system which fixes the encapsulating and dielectric multi-layer element by contact on single surface portions. 
     
     
       6. The system of  claim 4 , wherein said automatic picking device comprises through-openings and an indirect heating system so as to activate adhesion in said third station. 
     
     
       7. A process for producing conductive backsheets for photovoltaic panels with a back-contact architecture, the conductive backsheets having an integrated encapsulating and dielectric layer, the process having operating phases and control checks, wherein the phases are related to a secondary working process for an encapsulating and dielectric multi-layer element, the process comprising:
 loading on a tray a single sheet of the conductive backsheet with a conductive layer facing upwards, the step of loading being carried out in a first station by taking the single sheet from the pile of sheets upstream of the step of loading; 
 checking a position of the conductive backsheet on the tray; 
 superimposing and fixing of the encapsulating and dielectric multi-layer element on the conductive backsheet, wherein superimposing is carried out by loading the encapsulating and dielectric multi-layer element in a synchronized manner directly from a secondary line by an automatic picking device which orientates the encapsulating and dielectric multi-layer element according to an actual position with respect to the conductive backsheet as detected by an integrated control system, the step of fixing is also carried out by the encapsulating and dielectric multi-layer element being firmly connected with pressure and heating by the automatic picking device which releases the encapsulating and dielectric multi-layer element only when the fixing has been carried out so as to obtain a finished conductive backsheet with an integrated encapsulating and dielectric layer, and wherein the heating activates an adhesive in contact with the conductive backsheet; 
 checking and unloading a finished product from the tray so as to deliver the finished product to a storage of compliant products or to a storage of non-compliant products by way of a continuous conveying system; 
 preparing the encapsulating and dielectric multi-layer element upstream of the secondary line by cutting; 
 drilling the encapsulating and dielectric multilayer element; 
 checking and controlling the drilling and positioning of the encapsulating and dielectric multi-layer element for the purpose of calibrated superimposition on the conductive backsheet; and 
 synchronizing the loading of the drilled encapsulating and dielectric multi-layer element for the calibrated superimposition by the automatic picking device. 
 
     
     
       8. The process of  claim 7 , further comprising:
 checking and controlling positions of the drilled holes; and 
 arranging the contacts for a back junction box by inserting contacting conductive elements. 
 
     
     
       9. The process of  claim 7 , wherein the fixing occurs by selective direct heating of by contact with a rapid modulable-growth temperature transient being between room temperature and 150° C. in a time of between 15 seconds and 1 minute. 
     
     
       10. The process of  claim 7 , wherein the fixing occurs with indirect heating by at least one external radiation source which is combined with said automatic picking device.